Single digit selector



Oct. 19, 1965 H. A. STICKEL 3,213,425

SINGLE DIGIT SELECTOR Filed March 26, 1962 4 Sheets-Sheet 1 ml v i IMO 76 IN V EN TOR. #4 2040 A r/a a Oct. 19, 1965 H. A. STICKEL 3,213,425

SINGLE DIGIT SELECTOR Filed March 26, 1962 4 Sheets-Sheet 2 INVENTOR. 1 0120.40 4. 57/0651 BYmqvXgc 4 Oct. 19, 1965 H. A. STICKEL SINGLE DIGIT SELECTOR 4 Sheets-Sheet 4 Filed March 26, 1962 INVENTOR. #4 2010 A fr/a a United States Patent 3,213,425 SINGLE DIGIT SELECTOR Harold Adolph Stickel, 250 22nd Ave, San Francisco, Calif. Filed Mar. 26, 1962, Ser. No. 182,557 6 Claims. (Cl. 340164) This invention relates in general to a selective signal receiving device and more particularly to a device capable of receiving a coded electrical signal consisting of a series of integers which may include the number 1.

Various devices have been described for receiving and decoding electrical signals consisting of a series of integers. Such devices find utility as call selectors in communications systems, e.g., telephone systems having a common wire and also in telemetering and remote control systems. See, for example, United States Patents 2,575,198; 2,595,614; and 2,947,974. Structures of the patents mentioned all have the common deficiency that they are not capable of responding accurately to integer signals containing the digit 1.

It is therefore an object of this invention to provide a selective signal receiving device which is capable of responding accurately to signals containing the integer 1, thereby making available a substantially larger number of integer signal combinations than has been available heretofore.

It is a further object of this invention to provide an electro-mechanical selective signal receiving device which is so constructed that incorrect signals cause a minimum of unnecessary motion of moving parts thereof whereby to minimize wear and maximize the useful life of the code selector.

Other objects and advantages of this invention, if not specifically set forth, will become apparent during the description which follows.

In the drawings:

FIGURE 1 is a perspective view of a preferred embodiment of the present invention.

FIGURE 2 is a partially sectional side elevational view of the structure of FIGURE 1 taken generally from the opposite side of the device shown in FIGURE 1.

FIGURE 3 is a plan view of the structure of this invention with the code plate partially broken away.

FIGURE 4 is a plan view similar to FIGURE 3 with additional parts removed whereby to reveal further the interior structure.

FIGURES 5-8 are shematic representations of the relationships of various of the moving parts at different stages during the operation of the device.

FIGURES 9 and 10 are partial side elevations showing various of the moving parts at different stages during the operation of the device.

FIGURE 11 is a diagram of a wiring arrangement.

Fundamental to the decoding procedure is the movement of a memory element or code plate from one bit or pulse position to the next by means of a drive unit control by the incoming pulses whether from a communication channel or from a pulse generator so that the incoming signal may be compared bit by bit, pulse by pulse with the code stored in the memory element. Coincidence between the incoming signal and the code stored in the memory element causes the memory element to be placed in a position which will produce an alarm signal. When so used, the following actions take place: provided that the conditions of pulse rate, pulse amplitude, percent mark time, etc., are within tolerance limits, the coded pulse selector is discriminatory only in the sense that it counts pulses in the order which they come in and compares the individual digit count to the digit count of a code which has been preset into the 3,213,425 Patented Oct. 19, 1965 memory. If each digit or consecutive train of pulses coming into the selector is identical to the digits of a code stored in the memory, the selector will code and provide an alarm signal by making an electrical contact; but not if any digit in the incoming signal is not identical in pulse count and digital position to the code which is set into the memory element.

If any stored digit at a given position in the memory element does not coincide with the incoming digits, advancement of the memory element is stopped, and the memory element is moved to the start of the first digit position which will in effect reject the incoming signal by precluding full advancement of the memory element. During the train of pulses the memory element is allowed to move only unidirectionally, the drive unit providing the forward motion and the latch unit preventing retrograde motion of the memory element. Either of two conditions will cause the memory element to reset, and thus reject the coded signal: (1) When the pulse train on any given digit of an incoming signal ceases before complete advancement of the memory element to the next digit position. This is known as undercount. (2) Continuation of the pulse train by one or more bit positions beyond the next digit position; this is known as overcount.

Condition (2) requires that some means he provided to prevent the memory element from advancing beyond the next digit position to preclude the possibility of moving the memory element to the digit position next in line. This is known as overcount protection.

In the device to be described in greater detail hereinafter, there is provided a movable control plate and propelling means for the control plate. The control plate carries two or more preset pins, and plate and pins together constitute the aforementioned memory element. The propelling means incorporates a pawl for engaging the control plate and driving the plate in small uniform increments and a pulsing armature operatively associated with the pawl whereby at the outset of each pulse of the pulsing armature, the pawl is withdrawn from engagement with the control plate and released for re-engagement with the control plate at the termination of the pulse. Advancement of the control plate is assured by the provision of a resilient means which urges the pulsing armature to a normal position on termination of the pulse, the resilient means moving the pulsing armature a sufiicient distance to allow the pawl associated therewith to advance the control plate one of said uniform increments unless the control plate is blocked from advancing by the aforementioned overcount protection means. In this use the pawl is locked in engagement with the control plate and will urge the plate forward if the overcount protection means is deactivated. As in the devices described in the abovementioned patents, means are provided for assuring that the device is receptive to a predetermined code signal composed of a series of integers and at the completion of the predetermined series of integers, a contact element carried by the control plate permits a circuit to be closed whereby to operate an electrical switch or mechanism at a remote station to energize a visual or oral signal or to perform some function.

The device of the present invention differs functionally from those most closely related which have been available heretofore in that it is capable of responding correctly to integer signals containing the digit 1. In structures available heretofore, it has always been necessary that the preset pins be positioned at least two of the aforementioned uniform increments apart. In these structures, if the pins were only one increment apart, an incorrect code sequence incorporating, for example,

II) the integer 7 could be responded to where the decoder actually had been preset to the sequence 6-1. In other words, under certain circumstances the fdevice could not discriminate between code signals incorporating two integers in sequence, the last of which was the digit 1, such as 1, and signals which incorporated at a particular position in the code sequence an integer which was the sum of the aforementioned two numbers in sequence, 6.

Referring now to the drawings wherein like characters refer to like parts throughout, there is shown a control element or plate 12 having a series of equidistantly spaced notches 14 about the periphery thereof. The plate is mounted about a hub 16 (see FIGURE 2) having a collar 18 thereon. The hub 16 is loosely mounted for rotation about sleeve 20 which is supported by spindle 22, in turn tapped for receipt of screw 24 which serves as means for holding the sleeve 20 thereon. Circular washer 26 is held in place by the split washer 28 which retains hub 16 in place about the sleeve 20. Plate 30 is fixed about the lower portion of sleeve 20 and will not rotate relative thereto while spindle 22 is fixed to plate 32 by means of cooperating flange 33 and head 34. A nylon stud 36 passes through plates 30 and 32 so as to prevent relative rotation thereof. Plate 31) is provided with an upstanding flange 38 which cooperates with depending pin 40, in turn, secured on the underside of the code plate 12 to prevent clockwise movement of the code plate 12 beyond a predetermined point.

Channel-shaped collar 42 frictionally engages hub 16. The outstanding flanges of the collar grasp and hold the innermost portion of spiral spring 44 in place. The other end of the spring is crimped about pin 45, in turn mounted on plate 30 (see FIGURE 3). Thus, the spring tends to rotate the code plate 12 in a clockwise direction until rotation is stopped through the action of flange 38 and pin 40.

Plate 32 is secured to the frame of the device by stud 36, aforementioned, and by means of an additional stud 46 (see FIGURE 3). As may best be seen in FIGURE 4, the frame consists of a pair of L-shaped steel members 48 and 50 held in a back-to-back relationship by rivet 52. L-shaped member 48 is provided with brackets 54 and 55 (FIG. 2) and L-shaped member 50 is provided with brackets 56 and 57 (FIG. 2), each of which serve to support additional parts to be described hereinafter.

Secured to the short arm of L-shaped frame member 50 is stud 64 which supports inductor 66 and nylon spacer 67. In like fashion, stud 68 is secured to frame member 48 and supports inductor 70 thereon. Inductor 71) is provided with means for slowing the collapse of magnetic flux when the flow of current is ceased therethrough, a copper slug 72 and/or rectifier 73 (FIG. 11) being suitable means of achieving this. Pivoted to brackets 54 and 55 by means of nylon pin 36 is armature 76 which preferably has rlvetted thereto a brass facing plate 78. To the opposite side of the device is pivoted slowreleasing armature 80 by means of pin 46 passing through holes in brackets 56 and 57. Spring 82 is secured at one end thereof adjacent bracket 55 and to the slow moving armature at the other whereby to urge the slowmoving armature away from the inductor 70.

Armature 76 supports a bracket on the opposite end thereof through which passes pin 96 about which pivots yoke 98 which in turn supports driving pawl 100. Spring 102 is crimped about pin 96 at one end and crimped at the other end thereof about plate 32 (see FIGURES 2 and 3) and provides sufficient tension to return the armature 76 to a rest position when current flow through inductor 66 is terminated and the field thereof collapses. The driving pawl thus advances the code plate 12 the width of one notch 14 immediately following collapse of the magnetic flux in the inductor 66, the plate being driven through the reaction of spring 102. The pawl is withdrawn from the notch when current is first supplied to the inductor. The result is a :11 more uniform driving action than has been possible with the structures of the aforementioned patents in that the spring can be depended upon to move the pawl in a uniform manner, independent of current fluctuations through the windings of inductor 66.

Armature 80 also supports a number of moving parts. The bracket 104 has an extension 105 and pivotally mounted in the bracket 194 is the rod 106 which supports the pawl 167. The spring 108 urges the pawl 107 inwardly so that it normally rests in one of the notches 14- of the code plate 12. Contact arm 110, having contact pin 112 thereon, is pivoted about pivot point 114. Screws 116 are grounded to the armature and hold the arm 116* to U-shaped bracket 118, in turn pivoted to plate 32 by means of stud 114. The bracket 118 is loosely secured at the opposite end thereof to flange 120 of the slow-releasing armature 80 by means of sliding pin 122. Action of the slow-releasing armature thus causes U-shaped bracket 118 to pivot about stud 114 and arm 11th is thus similarly pivoted. The arm 110 is insulated from bracket 118 by means of fiber insulators and is also insulated from screws 116. A soldering lug 126 is positioned between one of the fiber insulators and the surface of arm 110.

Spring 128 is crimped at one end about pin 122 and passes directly above plate 34, thereafter to be crimped about the sleeve 130 which is mounted coaxially about driving pawl 100. The spring serves to insure that the driving pawl is normally maintained in engagement with one of the notches 14 of the code plate 12.

Attention is now directed to FIGURE 4 which is similar to FIGURE 3 but which, in addition, shows the internal structure of the device, code wheel 12, plates 30 and 34 being removed. Pin 152 is supported by a horizontal bracket 154 which is mounted midway between the ends of armature S0. Secured partially by means of pin 152 to horizontal bracket 154 is plate 156 having an upstanding ear 158 and an outstanding (horizontal) pin 159 thereon. A second upstanding ear 160 serves as the means for contacting pawl 107 (see FIGURE 3) whereby to cause retraction thereof when the slow-releasing armature 81 returns to its normal position. Pivoted to plate 156 by means of pin 162 is a second plate 164 having an arcuate arm thereon from which extends an upright blocking element or flag 166. Pin 162 also passes through the other end of the plate 156 and with pin 152 prevents movement of plate 156 relative to plate 154.

Coil spring 167 is secured at either end thereof to the fingers of plates 156 and 164 so as to urge plate 164 in a clockwise direction relative to plate 156 until stopped by the action of pin 152, as seen in FIGURE 4. Horizontal pin 159 is so positioned on plate 156 that it will contact upstanding flange 166 when the latter is pivoted to a point just beyond ear 158, as shown in FIGURE 6 and preferably a radial distance which is equivalent to less than two notches of the code plate. Most preferably, the pin 159 or other functionally equivalent blocking means is so placed that the flag 166 can be pivoted a distance equal to just one notch 14 of the code plate 12. Plate 164 is provided with a tangential extension 169 which is closely adjacent a downwardly depending portion of the pawl 101i and it may be seen that when the plate 164 is rotated in a counterclockwise direction, the pawl will be moved away from one of the notches 14 of the plate 12 against the resistance of spring 128.

The code wheel 12 is provided with one or more downwardly depending pins 170 (see FIGURE 1) which represent the lowermost extremities of L-shaped coding elements 172. A plurality of holes 173 are provided about the periphery of the code wheel 12 whereby to permit the re-positioning of the individual code pins 170 so as to make possible a selection of a wide variety of codes, precisely as described in Patent 2,947,974. There is also provided a contact pin having an upstanding portion 176 and a downwardly depending portion 178, again similar to the structure shown in the aforementioned patent. The location of this contact pin may also be changed at will so as to provide a variety of terminal digits. One end of each pin is forced between collar 18 and the surface of code plate 12 so as to retain the pins frictionally in the desired positions. The blocking element or flag 166 is so positioned relative to the downwardly depending pins 170 and 178 that the flag 166 will be contacted thereby as the code wheel is rotated.

Suitable adjustment screws, 180, are provided for purposes of adjusting the throw of both the slow-releasing armature 80 and the pulsing armature 76.

The device is adjusted so that the slow-releasing armature will not release between cycles within a code group but will release between code groups. Thus, the length of each pulse is not critical but the space between pulses within a code group must not exceed the retention time of the slow-releasing armature, While the space between code groups is not critical so long as it is long enough to allow the slow-releasing armature to assume a partially released position, as will be described hereinafter.

A code is selected as, for example, the 5-1-107 shown in FIGURE 1 and the armatures 76 and 80 are in the rest position of FIGURE 11 and the code wheel 12 is in a fully clockwise position, as seen in FIGURE 1. An open circuit telephone dial of the type shown in FIGURE 7 of the Stickel Patent 2,575,198, and here identified as 190, dialed to the digit 5. Battery 192 serves as a source of direct current and five discrete current pulses are applied to inductor 66 with the result that the armature 76 is pulsed five times. At the outset of the first pulse, pawl 100 is urged into a notch 14 by the action of spring 128 and arm 105, as seen in FIGURE 6. Inductor 70 is wired in series with inductor 66 and, therefore, the slow-moving armature 80 is also attracted to one end of the coil 70. The flux of coil 70 decays at a slower rate than that of coil 66 following cessation of current flow due to the action of slug 72 and/or rectifier 73. Thus, armature 80 remains continually in a closed position as armature 76 pulses the prescribed number of times. After each pulse, pawl 107 is urged into one of the notches 14 so as to prevent the code wheel 12 from being reset. Following receipt of four pulses, the relationship of certain of the moving parts will be that shown in FIGURE 5 with the lowermost portion of pin 170 approaching the blocking member or flag 166. On receipt of the fifth pulse, the blocking member is swung counterclockwise about pivot point 162, as shown in FIGURE 6. Cessation of the rapid series of pulses allows slow-moving armature 80 to retract somewhat to a partially released position with the result that blocking member 166 is swung out of the path of pin 170. Upstanding car 158 then contacts the pin 170, as shown in FIGURE 9, so as to prevent the slow-releasing armature 80 from returning fully to its original rest position, the upstanding ear 158 being, as aforementioned, supported by plate 156, the action of which is also dependent upon slow-releasing armature 80. Had a signal of less than five been received, contact between pin 170 and ear 158 would not have been achieved as pin 170 would not have been in the path of car 158 on release of slow-moving armature 80 and the slow-releasing armature would have returned to its original rest position, thereby retracting pawl 107 from one of notches 14 and allowing code wheel 12 to be reset under the influence of spring 44. Had a larger number than five been received, passage of pin 170 would have been blocked by the action of blocking mem bet or flag 166 which, at no time, would have had an opportunity to pivot to one side through partial release of armature 80. The pin 159 stops the rotation of flag 166 when pin 170 is on the same radius line of the wheel 12 as at least a portion of upstanding ear 159. Preferably, the flag 166 pivots a distance equivalent to the distance covered when the wheel 12 is advanced the width less than two notches, and most preferably, one notch and is returned to the position shown in FIGURE 1 by a spring 167 at the time the code wheel returns to its rest position. However the distance that flag 166 pivots is of no great importance as long as, at the conclusion of the pivoting action, the relationship of flag 166, pin 170a and ear 158 is as shown in FIGURE 6. If further pivoting of flag 166 were permitted, release of the slow-moving armature would permit ear 158 to come into contact with the second of pins 170a, thus responding to the incorrect digit 6 rather than solely the correct sequence of 5-1. In the preferred structure shown in FIGURES 58, following receipt of five sequential pulses, the relationship of parts is as shown in FIGURE 5. Pawl is in notch 14a. of code wheel 12 and spring 102 is urging armature 76 in a counterclockwies direction. The flag 166 is contacted by pin a and pivots a distance equivalent to one notchs width as spring 102 urges the pawl forward (see FIGURE 6). Another pulse causes the pawl 100 to be withdrawn and to engage notch 14b of code wheel 12. The pawl 100, as shown in FIGURE 7, cannot disengage itself from the notch 14b since it is already pivoted to a maximum clockwise extent while the spring 102 urges it in a counterclockwise direction exerting pressure on the pawl through assembly 98, thus continuing to urge or bias the code wheel forwardly one notch. But such motion is prevented by the fact of ear 166 being pivoted to the point of Contact with pin 159 and hence, until such time as the slow-moving armature 80 is permitted to return to a rest position on cessation of the current flow through the inductor 70, the pulsing armature 76 will remain in a relatively fixed position wherein one end thereof is closely adjacent the inductor 66. A further series of pulses through inductor 66 thus does not tend to wear the pivot points of armature 76 as no further substantial motion thereof can be accomplished until code wheel 12 is reset. This is accomplished by releasing slowmoving armature 80, thereby withdrawing flag 166 from the path of the pin 170 with the result that spring 102 urges the pulsing armature 76 into a rest position, thereby causing the pawl 100 to advance the code wheel. The ear 158 which has previously been engaged with pin 170 and which is necessarily narrower than the space between two adjacent pins 170 and 170a mounted in adjacent holes of the code wheel passes between these two pin ends during the single notch advancement of the code plate. See FIGURE 8 which shows this taking place. The code wheel is thus released and is reset under the influence of spring 44. If the upstanding car 158 is slightly bent as shown in FIGURE 4, this will facilitate passage of the ear between adjacent pins 170 and 170a by insuring against the possibility of the ear becoming engaged with the second of the pins 170a rather than passing between the two adjacent pins.

When the correct code is dialed, in this case 5-1-10-7, the code wheel advances to the first position represented by a code pin 170 positioned in the fifth hole of the wheel 12. The pulses are interrupted long enough to allow the slow-moving armature 80 to release somewhat and the flag 166 is withdrawn 'from the path of the first of the pins 170a. Thus, engagement between ear 158 and the first of the code pins 170a results, as shown in FIGURE 9. Continuation of the code sequence 1-10 causes repetition of the just-described sequence of events. As shown in FIG- URE 1, the device here represented requires the digit 7 to complete the code. Optionally, downwardly depending pin 178 may advance and contact the blocking member 158 in the same manner as described above with respect to the pin 170. However, on partial release of the slow-moving armature following the digit 7 the contact pin 112 supported by arm 110, in turn dependent upon the movement of the slow-releasing armature 80, is brought into direct contact with the upstanding portion 176 of the contact pin 174. This condition is depicted in FIGURE 10. The circuit would thus be completed from the soldering lug 126, through arm 110, pin 112,

pin 176 and finally through the body of the decoder to screw 116. As shown in FIGURE 11, current will then be supplied to lamp 188 and a signal made available for the operation of one or more switches or other mechanisms.

A pulse can be sent through inductor 66 without also passing through inductor 70 by the action of reset switch 194 and, since this does not cause the slow-moving armature to be pulsed, assures that there will be no interlocking between a pin 170 and upstanding ear 158 should there be a pin 170 in the next hole of the code plate 12. This permits the code wheel to be reset by a single pulse after receipt of a signal such as l-10 which is similar to the code signal to which the selector is set, but which lacks one or more terminal integers thereof, thus causing the code wheel to be rotated to a partially advanced position as shown in FIGURE 9.

Obviously, many modifications and variations of the invention as hereinabove set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A selective code signal receiving device responsive to a predetermined group of pulses comprising:

(a) a movable control plate;

(b) means actuated by said pulses for advancing said control plate in step-wise increments from a normal position to an advanced position corresponding to a first pulse group having a predetermined number of pulses on receipt of said first pulse group, and thereafter from said advanced position to a farther advanced position corresponding to an additional pulse group having a predetermined number of pulses on receipt of said additional pulse group;

(c) means for preventing the advancement of said control plate beyond said first mentioned advanced position operative when the pulses in said first pulse group are in excess of the predetermined number of pulses in said first pulse group;

(d) and means for biasing said control plate in the direction of advancement when said means to prevent advancement of said control plate is operative, said biasing means being inoperative when said first pulse group corresponds to said first advanced position.

2. A selective code signal receiving device comprising:

(a) a movable control plate having a series of equidistantly spaced notches along an edge thereof;

(b) a pawl for engaging the said notches and driving the said control plate solely in notch-wide increments from a normal position to an advanced position on receipt of a first pulse group, and thereafter from said advanced position to a farther advanced position on receipt of an additional pulse group;

(c) means for normally holding said pawl in engagement with a notch of said control plate;

(d) pulsing means connected to the said pawl whereby at the outset of each pulse, said pawl is withdrawn from one of said notches and engaged with a previous notch of said plate;

(e) resilient means urging said pulsing means to a normal position on termination of each of said pulses whereby to urge said pawl to advance said control plate one notch and to continue to bias said control plate in a forward direction if advance of said con trol plate for at least the width of one notch is blocked;

(f) a member carried by said control plate at a point corresponding to said first mentioned advanced position of said control plate;

(g) a slow-releasing element responsive once to a pulse group and releasing upon the completion of said p;

(h) a blocking element carried by said slow-releasing element, said blocking element obstructing the path of the said member when the said slow-releasing elemen is actuated and moving out of the path of the said member upon a partial release movement less than full release of the said slow-releasing element, said blocking member being pivoted to said slowreleasing element whereby to permit said blocking member to pivot a small distance less than the distance covered by said control plate as the result of two pulses;

(i) a second pawl responsive to the position of the slow-releasing element to engage said movable control plate and prevent retrograde movement of the control plate except when the slow-releasing element is fully released;

(j) a contact member carried by said control plate;

(k) and a second contact member fixed generally in the path of said first contact member, said contact members being so positioned that when said control plate is at said farther advanced position, said contact members are adjacent one another.

3. A selective code signal receiving device comprising:

(a) a movable control plate having a series of equidistantly spaced notches along an edge thereof and a plurality of holes therein each one notch apart;

(b) a pawl for engaging the said notches and driving the said control plate solely in notch-wide increments from a normal position to an advanced position on receipt of a pulse group, thereafter from said advanced position to a subsequent advanced position on receipt of an additional pulse group, and thereafter to a farther advanced position on receipt of a last pulse group;

(c) means for normally holding said pawl in engagement with a notch of the said control plate;

(d) pulsing means connected to said pawl whereby at the outset of each pulse said pawl is withdrawn from one of said notches and engaged with a previous notch of said plate;

(e) resilient means urging said pulsing means to a normal position on termination of each of said pulses whereby to urge said pawl to advance said control plate one notch and to continue to bias said control plate in a forward direction if advance of said control plate for at least the width of one notch is blocked;

(f) members mounted in adjacent holes of the said control plate at points corresponding to said two first-mentioned advanced positions of said control plate;

(g) a slow-releasing element responsive once to a pulse group and releasing upon the completion of said pulse p;

(h) a blocking element carried by said slow-releasing element, said blocking element obstructing the path of the said members when the said slow-releasing element is actuated and moving out of the path of said members upon a partial release movement less than full release of the said slow-releasing element, said blocking member being pivoted to said slow-releasing element for pivotal movement through a small distance less than the distance covered by said control plate as a result of two pulses;

(i) a second pawl responsive to the position of the slow-releasing element to engage said movable control plate and prevent retrograde movement of the said control plate except when the slow-releasing element is fully released;

(j) a contact member carried by said control plate at a point corresponding to said last advanced position;

(k) and a second contact member fixed generally in the path of said first contact member, said contact members being so positioned that when said control element is at said last advanced position, said contact members are adjacent one another.

4. A selective code signal receiving device comprising:

(a) a movable control plate having a series of equidistantly spaced notches along an edge thereof and a plurality of holes therein each one notch apart;

(b) a pawl for engaging the said notches and driving the said control plate solely in notch-wide increments from a normal position to an advanced position on receipt of a pulse group, thereafter from said advanced position to a subsequent advanced position on receipt of an additional pulse group, and thereafter to a farther advanced position on receipt of a last pulse group;

() means for normally holding said pawl in engagement with a notch of the said control plate;

(d) pulsing means connected to said pawl whereby at the outset of each pulse said pawl is withdrawn from one of said notches and engaged with a previous notch of said plate;

(e) resilient means urging said pulsing means to a normal position on termination of each of said pulses whereby to urge said pawl to advance said control plate one notch and to continue to bias said control plate in a forward direction if advance of said control plate for at least the width of one notch is blocked;

(f) members mounted in adjacent holes of the said control plate at points corresponding to said two firstmentioned advanced positions of said control plate;

(g) a slow-releasing element responsive once to a pulse group and releasing upon the completion of said pulse p;

(h) a blocking element carried by said slow-releasing element, said blocking element obstructing the path of the said members when the said slow-releasing element is actuated and moving out of the path of said members upon a partial release movement less than full release of the said slow-releasing element, said blocking member being pivoted to said slow-releasing element for pivotal movement through a small distance less than the distance covered by said control plate as a result of two pulses;

(i) a second pawl responsive to the position of the slowreleasing element to engage said movable control plate and prevent retrograde movement of' the said control plate except when the slow-releasing element is fully released;

(j) a contact member carried by said control plate at a point corresponding to said last advanced position;

(k) a second contact member fixed generally in the path of said first contact member, said contact members being so positioned that when said control element is at said last advanced position, said contact member contact one another;

(1) and means mounted on said slow-releasing element for engaging said members mounted on said control plate and preventing full release of said slow-releasing element when in engagement therewith, said means being capable of passing between said members held in adjacent holes of said control plate.

5. An electric, selective code signal receiving device comprising:

(a) a circular, rotatably mounted biased control plate having a series of notches evenly spaced about the periphery thereof and a plurality of holes also about the periphery thereof spaced one notch apart;

(b) a pawl for engaging the said notches and driving said control plate solely in notch-wide increments from a normal position to an advanced position on receipt of a first pulse group, thereafter to a subsequent advanced position on receipt of an additional pulse group and thereafter to a last advanced position on receipt of a last pulse group;

(0) means for normally holding said pawl in engagement with a notch of the said control plate;

(d) a pulsing armature connected to the said pawl whereby at the outset of each pulse of said pulsing armature, said pawl is withdrawn from one of said notches and engaged with a previous notch of Said plate;

(e) resilient means urging said pulsing armature to a normal poistion on termination of each of said pulses whereby to cause said pawl to advance said control plate one notch and to continue to bias said control plate in a forward direction if advance of said control plate for at least the width of one notch is blocked;

(f) members mounted in adjacent holes of said control plate at points corresponding to said two first-mentioned advanced positions of said control plate;

(g) a slow-releasing armature responsive once to a pulse group and releasing upon completion of said p;

(h) each of said armatures being operatively associated with an inductor;

(i) a blocking element carried by said slow-releasing armature, said blocking element obstructing the path of said members carried by said control plate when the said slow-releasing armature is actuated and moving out of the path of said members upon a partial release movement less than full release of the said slow-releasing armature, said blocking member being pivoted to said slow-release armature for pivoting movement through a distance at least equivalent to a distance covered by said control plate as the result of a single pulse of the pulsing armature and less than the distance covered by said control plate as the result of two pulses of the said pulsing armature;

(j) a second pawl responsive to the position pawl of the slow-releasing armature to engage said movable control plate and prevent retrograde movement of the control plate except when the slow-releasing armature is fully released;

(k) means mounted on said slow-releasing armature for engaging said members carried by the said control plate and preventing full release of said slowreleasing armature when in engagement therewith, said means being narrower than the distance between two adjacent holes on the said control plate;

(1) a contact member carried by said control plate at the said last advanced position;

(in) and a second contact member fixed generally in the path of said first contact member, said contact members being so positioned that when said control plate is at said last advanced position, said contact members contact one another.

6. An electric, selective code signal receiving device comprising:

(a) a circular, rotatably mounted biased control plate having a series of notches evenly spaced about the periphery thereof and a plurality of holes also about the periphery thereof spaced one notch apart;

(b) a pawl for engaging the said notches and driving said control plate solely in notch-wide increments from a normal position to an advanced position on receipt of a first pulse group, thereafter to a subsequent advanced position on receipt of an additional pulse group and thereafter to a last advanced position on receipt of a last pulse group;

(c) means for normally holding said pawl in engagement with a notch of the said control plate;

(d) a pulsing armature connected to the said pawl whereby at the outset of each pulse of said pulsing armature, said pawl is withdrawn from one of said notches and engaged with a previous notch of said plate;

(e) resilient means urging said pulsing armature to a normal position on termination of each of said pulses whereby to cause said pawl to advance said control plate one notch and to continue to bias said control plate in a forward direction if advance of said control plate for at least the width of one notch is blocked;

(f) members mounted in adjacent holes of said control 1 1 plate at points corresponding to said two first-mentioned advanced positions of said control plate;

g) a slow-releasing. armature responsive once to a pulse group and releasing upon completion of said (h) each of said armatures being operative'ly associated with an inductor;

(i) a blocking element carried by said slow-releasing armature, said blocking element obstructing the path of said members carried by said control plate when the said slow-releasing armature is actuated and moving out of the path of said members upon a partial release movement less than full rel-ease of the said slowreleasing armature, said blocking member being pivoted to said slow-release armature for pivoting movement through a small distance less than the distance covered by said control plate as the result of two pulses of the said pulsing armature;

(j) a second pawl responsive to the position pawl of the slow-releasing armature to engage said movable control plate and prevent retrograde movement of the control plate except when the slow-releasing armature is fully released;

(k) means mounted on said slow-releasing armature for engaging said members carried by the said control plate and preventing full release of said slowreleasing armature when in engagement therewith, said means being narrower than the distance between two adjacent holes on the said control plate;

(1) a contact member carried by said control plate at the said last advanced position;

(m) a second contact member fixed generally in the path of said first contact member, said contact members being so positioned that when said control plate is at said last advanced position, said contact members contact one another;

(n) and means for separately applying an electrical pulse to said inductor associated with said pulsing armature without applying an electrical pulse to said inductor associated with said slow-releasing armature.

NEIL C. READ, Primary Examiner. 

1. A SELECTIVE CODE SIGNAL RECEIVING DEVICE RESPONSIVE TO A PREDETERMINED GROUP OF PULSES COMPRISING: (A) A MOVABLE CONTROL PLATE; (B) MEANS ACTUATED BY SAID PULSES FOR ADVANCING SAID CONTROL PLATE IN STEP-WISE INCREMENTS FROM A NORMAL POSITION TO AN ADVANCED POSITION CORRESPONDING TO A FIRST PULSE GROUP HAVING A PREDETERMINED NUMBER OF PULSES ON RECEIPT OF SAID FIRST PULSE GROUP, AND THEREAFTER FROM SAID ADVANCED POSITION TO A FARTHER ADVANCED POSITION CORRESPONDING TO AN ADDITIONAL PULSE GROUP HAVING A PREDTERMINED NUMBER OF PULSES ON RECEIPT OF SAID ADDITIONAL PULSE GROUP; 